Special patented devices containing silicon-based microelectrode arrays have been inserted into the cortex of patients in order to cure spinal cord injury, and the devices have been shown to stimulate a stable population of cortical neurons on a long-term basis. Similar devices might be ultimately used in a wide range of injuries to the central nervous system. However, these widely used silicon-based devices can easily generate debris particles, and when devices are implanted into human bodies, these debris could cause local damage and inflammation. Therefore, it is desirable to explore other biomaterials with better mechanical, thermal, chemical and tribological properties that may be suitable to replace the silicon-based devices generally used in biomedical applications.
Ultra-nanocrystalline diamond (UNCD) films with grains of 2-5 nm and a smooth surface of 10-20 nm root-mean-square (RMS) are candidates for use in the fabrication of multifunctional devices, such as for microelectromechanical systems (MEMS) that require a high Young's modulus, low friction coefficient and high resistance to wear. UNCD films could also be used in biomedical devices requiring bioinertness and non-cytotoxicity. Combining these superior characteristics, UNCD is a potential material for use in biomedical devices such as bioMEMS. Diamond coatings have the chemical inertness and impermeability required to reduce the crevice corrosion that is commonly seen in conventional metallic implants. Recently, the suitability and noncytotoxicity of ultra-nanodiamond films as a support surface for cell growth and proliferation has been proven. Moreover, Xiao et al. demonstrated the successful insertion of UNCD bioinert encapsulation coatings of silicon microchips into human eyes. Responses of neural stem cells (NSCs) to nanoscale surface features and different electron affinities resulted from surface modification of UNCD films have not been studied.
A heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies, especially in connection with the method of identifying drug candidates for treating cancer, inflammatory diseases, and/or angiogenesis-associated diseases.